One of the key components of an effective home energy audit is infrared thermography. Infrared thermography (or infrared imaging, infrared diagnostics) consists of a thorough visual inspection of a home, including the basement, attic, and all the nooks and crannies, with an infrared camera which senses minute temperature differences. It essentially takes the guess-work out of pinpointing the drafts and the leaky spots within a home — registering, as it will, the exact temperature of various spots within the home. It provides you, the homeowner, with a precise visual representation of the air leaks and insulation problems in your home.
If a picture, as they say, is worth a thousand words, an infrared picture could very well be worth a thousand bucks, because it reveals the spots where your house is wasting energy (and money), and gives you clear directions for fixing them. Some of the imperfections in your home's thermal envelope will be obvious such as around windows and doors. However, chances are there will be some big surprises too, and that's part of what makes infrared imaging so valuable. You might discover that the constant draft in your living room could be taken care of with a simple bead of caulk along the baseboard, or that recessed light or bathroom fan was leaking so much air it was why your bathroom was hot or cold throughout the year.
For best results, there needs to be a temperature differential (delta T) between indoors and outdoors. Recommendations as to precise numbers differ, but you should talk to your auditor about an ideal differential for your region, climate and house. Often a high quality infrared camera, line the one used by Home Energy Medics, can be used effectively with a lower delta T.
Recessed light letting hot air in from the attic and leaky bathroom fan letting hot air in during the Summer.